Note, all the squares in the grid have
the same identical area. Geometric shapes do not change their
area simply because you move them, right? So how can the bottom
triangle gain a square?

The solution

If you can't figure it out, I'll tell you the solution, but
there's a catch: you first have to purchase something from Amazon.com through NoBeliefs.com.
(Perhaps unashamedly sneaky of me but this helps support
NoBeliefs.com and you get to read a good book.)

Just click on any Amazon banner, like the one below, (or any
book reference link from an article) from any page on NoBeliefs.com
and buy something from Amazon.com. You don't necessarily have
to buy a book; you can purchase a CD, video, or whatever you
want. After your order, just come back to NoBeliefs.com and go
to the email page and tell me what
you purchased and the date you purchased it, and ask for the solution to the puzzle. I'll then
send you to a solution. Don't worry, I'll know if you purchased
that item because Amazon tells me what got ordered (even though
they can't tell me who ordered it).

If you can't figure out what to buy, I highly recommend one
of the books from the Book Reviews.

If you click on the above banner (or any
other banner on the NoBeliefs.com site), and purchase something,
NoBeliefs.com will get a free donation from you.